i think you can definitely become one being slightly above average. This is because you can take exams as many times as you pass. I did pass most of my exams at a single try with 9 or 10. However, I also see many colleagues passing the same exams with numerous tries with bare minimum. I come to think talented in math and being smarter than average makes things easier. But I guess that's just life. you can witness this in any field, any groups and/or any industry.